feat(d3d12): add indirect command execution support

Added ICommandSignature and D3D12CommandSignature for indirect command execution in the D3D12 backend, with supporting types. Updated ICommandBuffer and IGraphicsEngine interfaces to support indirect execution and command signature creation. Refactored command buffer pooling in D3D12GraphicsEngine for more flexible reuse. Changed BeginFrame and EndFrame to void and clarified parameter names. Updated resource and frame data structures to use direct buffer indices. Added RenderingUtility for buffer and texture uploads. Removed IRenderOutput interface. Updated RenderSystem render loop and HLSL/C# code to match new buffer usage patterns.

BREAKING CHANGE: ICommandBuffer, IGraphicsEngine, and related APIs have changed signatures and behaviors. Indirect command execution is now supported and required for some advanced features.

src/Runtime/Ghost.Graphics.RHI/ICommandBuffer.cs

@@ -2,12 +2,10 @@ using Ghost.Core;
 
 namespace Ghost.Graphics.RHI;
 
-// TODO: Add ICommandAllocator support for thread local command buffers. We often use one allocator for multiple command buffers in a single frame.
-
 /// <summary>
 /// D3D12-style command buffer interface for recording rendering commands
 /// </summary>
-public interface ICommandBuffer : IDisposable
+public interface ICommandBuffer : IRHIObject
 {
     /// <summary>
     /// Gets the space of the command buffer.
@@ -25,12 +23,6 @@ public interface ICommandBuffer : IDisposable
         get;
     }
 
-    string Name
-    {
-        get;
-        set;
-    }
-
     /// <summary>
     /// Begins recording commands into this command buffer
     /// </summary>
@@ -182,9 +174,18 @@ public interface ICommandBuffer : IDisposable
     /// <summary>
     /// Dispatches ray tracing threads
     /// </summary>
-    // TODO: This method is not supported yet.
     void DispatchRay();
 
+    /// <summary>
+    /// Executes a sequence of GPU commands indirectly using the specified command signature and argument buffers.
+    /// </summary>
+    /// <param name="commandSignature">The command signature that defines the layout and type of commands to execute.</param>
+    /// <param name="argumentBuffer">A handle to the GPU buffer containing the arguments for each command.</param>
+    /// <param name="argumentOffset">The byte offset within the argument buffer at which to begin reading command arguments.</param>
+    /// <param name="countBuffer">A handle to the GPU buffer that specifies the number of commands to execute.</param>
+    /// <param name="countBufferOffset">The byte offset within the count buffer at which to read the command count.</param>
+    void ExecuteIndirect(ICommandSignature commandSignature, Handle<GPUBuffer> argumentBuffer, ulong argumentOffset, Handle<GPUBuffer> countBuffer, ulong countBufferOffset);
+
     /// <summary>
     /// Copies a specified number of bytes from the source graphics buffer to the destination graphics buffer.
     /// </summary>
@@ -204,5 +205,11 @@ public interface ICommandBuffer : IDisposable
     /// <param name="srcRegion">The region of the source texture to copy from. If null, the entire texture will be used.</param>
     void CopyTexture(Handle<GPUTexture> dst, TextureRegion? dstRegion, Handle<GPUTexture> src, TextureRegion? srcRegion);
 
+    /// <summary>
+    /// Updates the subresources of a GPU resource using data from the specified intermediate resource and subresource data spans.
+    /// </summary>
+    /// <param name="resource">A handle to the destination GPU resource whose subresources will be updated.</param>
+    /// <param name="intermediate">A handle to an intermediate GPU resource used to stage the subresource data before copying to the destination resource.</param>
+    /// <param name="subResources">A span containing the data for each subresource to update. Each element represents a subresource and its associated data.</param>
     void UpdateSubResources(Handle<GPUResource> resource, Handle<GPUResource> intermediate, params ReadOnlySpan<SubResourceData> subResources);
-}
+}